Apple’s A4, A5, and A5X chips have all been made using 45 nanometer transistors. At least that’s what we thought. According to a report from Chipworks, the $399 iPad 2 and the new 1080p enabled Apple TV are using a 32 nanometer version of the A5. Why is this important? Smaller transistors translate to smaller chips which means lower power consumption. It also lets companies clock their chips faster. But the most significant benefit is that it makes chips cheaper since you can yield more of them from per silicon wafer. Why didn’t Apple trumpet their move to 32 nanometer transistors? Probably because most people don’t care, but also because they wanted to experiment. The A5 in the $399 iPad 2 is the same A5 that was in the iPad 2 that’s been out on the market for over a year, except that Samsung built it at their 32 nanometer fabrication facility instead of their 45 nanometer facility. Apple likely wanted to see how well Samsung could handled the transition.

What does this tell us about the next iPhone? It’s guaranteed to have a 32 nanometer chip, though we don’t yet know if it’ll be a 32 nanometer version of the A5X in the new iPad or a brand spanking new A6 chip that uses ARM’s next generation Cortex A15 processor and PowerVR’s next generation Rogue architecture. Most of the Android phones that are due to come out this year will use Qualcomm’s new S4 platform, which is built using 28 nanometer transistors. It’d be foolish to assume that the A5X would end up in the next iPhone because of how big it is and how warm it runs. Brian Klug, the Mobile Editor at AnandTech, thinks the same:

Wow so people really think apple is gonna stick the A5X in the next iPhone? Sorry, I’ll be over here laughing my ass off at that rumor.